Genes and Alleles
DNA definition
Contains the specific instructions that make each type of living creature unique
What are phenotypes?
the appearance of an organism based on its genotype plus environmental factor
What are alleles?
the different forms of a gene; could be dominant or recessive
What are genotypes?
the genetic makeup of an organism
What does this allele grouping tell us: TT
two dominant alleles (Homozygous)
What does this allele grouping tell us: tt
two recessive alleles (homozygous)
What is the definition of hybrid?
When an organism has one dominant allele and one recessive allele
What is the definition of purebread?
When an organism has two of the same alleles for a trait
How are genes and alleles related?
an allele is a variant form of a gene. For each gene, parents pass one one allele.
examples of phenotype
hair color, eye color, height
Who is Gregor Mendel?
father of genetics who worked with pea plants to learn the basic patterns of inheritance.
What is the nucleus?
A small egg shaped structure inside the cell that contains chromosomes and genes
Examples of genotypes
AA, Aa, aa
What are chromosomes?
Thread-like structures found in the nucleus of a cell that contains all DNA
What does this allele grouping tell us: Tt
a dominant and recessive allele, the offspring will show the dominant trait (heterozygous)
What is a gene?
a stretch of DNA on a chromosome with instructions for one trait
DNA stands for
deoxyribonucleic acid
What are recessive alleles?
variation of a gene that will not show up when other alleles are present
What are dominant alleles?
variation of a gene that will show up even when other alleles are present